As disclosed by Clemens in U.S. Pat. No. 3,842,194, the first capacitance video disc system was a plastic disc with geometric variations corresponding to information of which the surface was coated with a thin metal layer and a thin dielectric layer.
After that, as disclosed in Japanese Patent Laid-Open No. 116,104/1978, Fox et al. attempted to produce video discs from polymers containing conductive particles such as conductive carbon black therein.
Khanna, as disclosed in U.S. Pat. No. 4,151,132, improved the conductive polymer compounds.
Martin et al., as disclosed in U.S. Pat. No. 4,228,050 improved the thermal stability of the above described conductive polymer compounds.
Martin et al., as taught in Japanese Patent Laid-Open No. 158,919/1980, tried to reduce the surface defects of video discs, to stabilize the playback performance and to keep the stamper long by pulverizing conductive carbon black agglomerates to the size of 0.44 mm or less.
Huck et al., as disclosed in Japanese Patent Laid-Open No. 83,854/1981, and Datta et al., as disclosed in U.S. Pat. No. 4,275,100, improved the moisture-proofness of capacitance video discs by rinsing the discs made of conductive polymer compounds with an aqueous solution to remove the water-soluble salts and oxygen-containing impurities from the surface of the video discs.